188 



The small red flowers which appear in May or June 

 are arranged in small terminal racemes. The fruit is a pod, 

 6 mm. in length, densely coated with white hairs and con- 

 taining 1 — 2 seeds. 



The leaf is isolateral in structure. The epidermis is 

 covered with bipartite hairs on short bases, and has stomata 

 on both sides, not sunk. There are 2 — 4 layers of palisade 

 cells (filled with starch) on each side, and 1 — 3 layers of 

 translucent cells surround the veins. The larger veins have 

 sclerenchyma on the phloem side. Sometimes, though rarely, 

 lignified bast-cells issue from this bast-sheath and traverse the 

 palisade layers till they reach the epidermis (fig. 34). "Speicher- 

 tracheiden" are found in great numbers in the mesophyll. 

 Among the palisade cells are a few translucent, globular 

 bodies which seem to consist of mucilage. 



The green bark of the young branches has 

 about 4 layers of short palisade cells below a 

 single-layered, hairy epidermis. Bast bundles 

 are found outside the vascular bundles. 



Closely related to Astragalus unifoliatas are 

 a number of other shrubby species of Astragalus 

 e. g. A. Ammodendron, paucijugus, hyrcanus, 

 villosissimus, macrocladus, brachijpus, squarrosus. 

 All belong to the section Ammodendron which 

 tion of leaf with is characterised by connate, clasping stipules, 

 anVr"'SpeU:h- ^^ ^ small inflated hairy and few- seeded pod 

 and by the frequency of persistent petioles. 

 The section belongs to the sub-genus Cercido- 

 thrix, characterised by bipartite hairs. A. brachylobus with 

 the same type of fruit, and A. sleroxijlon with linear, curved 

 pods also belong to this group. 



All the species named are early flowering shrubs or 

 dwarf shrubs with a few small and hairy leaflets. In some 

 of them the petiole persists till next summer though dead, 

 thus in A. paucijugus, hijrcanus, villosissimus, squarrosus and 

 perhaps others; in the first-named it attains a length of 

 about 30 centimetres. The shoots are often curved and the 

 bark in older branches is fibrous. In some of them the 



Fig. 34. Astra 



galas unifolia- 



tiis Part of 



transverse sec 



ertracheide" 

 X 71. 



